RE: Uplift calculation for gravity dam

"Hydrostatic pressures from reservoir water and tail water act on the dam and occur within the dam and foundation as internal pressures in the pores, cracks, joints, and seams. The distribution of pressure through a horizontal section of the dam is assumed to vary linearly from full hydrostatic head at the upstream face to zero or tailwater pressure at the downstream face, provided the dam has no drains or unlined water passages. When formed drains are constructed, the internal pressure should be modified in accordance with the size, location, and spacing of the drains............... For preliminary design purposes, uplift pressure distribution in a gravity dam is assumed to have an intensity at the line of drains that exceeds the tailwater pressure by one-third the differential between headwater and tailwater levels. The pressure gradient is then extended to headwater and tailwater levels, respectively, in straight lines. If there is no tailwater, the downstream end of a similar pressure diagram is zero at the downstream face. The pressure is assumed to act over 100 percent of the area. In the final dsign for a dam and its foundation, the internal pressures within the foundation rock and at contact with the dam will depend on the location, depth, and spacing of drains as well as on the joints, shears, and other geologic structures in the rock. Internal pressures within the dam depend on the location and spacing of the drains. These internal hydrostatic pressures should be determined from flow nets computed by electric analogy analysis, or other comparable means."

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Resources

ENGINEERING.com surveyed 364 product development professionals to glean insights into how their teams are performing today, and what technologies are most useful to support their processes. Download Now

3D printing has quickly expanded beyond the realm of prototyping and into the world of end part manufacturing. Desktop 3D printers need not be used for making parts themselves, but as a secondary process for producing tools. Download Now

Creating tooling for injection molding is an expensive and complex proposition. Until recently, the only way to avoid tooling defects causing air traps, voids, shrinkage and the like was to employ a time-consuming and tedious physical prototyping process. Download Now